The Scar
Down the center of the once united continent of Valecar lies a massive ravine known as "The Scar". No one knows how or why it is there, but people generally avoid it. The depth of it is unknown, because no one has ventured far enough and survived. Nobody knows what dwells deep within the scar, if anything at all.
There are only three points at which one can cross the Scar. Each of the bridges controlled by a different faction, each of which has grown in wealth exponentially since their bridge was completed. Taxing and controlling all flow of commerce in these chokepoints has led to their immense wealth. These chokepoints are known the be some of the most dangerous areas in all of Valecar, particularly for travelers & merchants. So much so that commerce is rarely traded across the Scar and a very individualized culture has emerged from the opposing sides. What is normal on the east culturally, may be entirely opposite in the west.

The Three Bridges of the Scar
Trade caravans, pilgrim convoys, and military patrols all funnel through just three crossings, each of which has grown into a fortified settlement that now profits from absolute control of movement:
What began as toll stations have become semi-sovereign city-states.
Safest vs Most Dangerous (Perceived/Rumor-based)
Safest: Bridge of Ashen Accord
Because religious order keeps violence suppressed — at least publicly.
Most Dangerous: Blackreach Causeway
Disappearances, contract killings, and forced indenture are common.
See also Rumors, Stories, and Theories